Message-ID: <2f8622b7-b5a3-241c-5f69-9d1a48e36e56@gmail.com>
Date:   Mon, 6 Mar 2023 09:31:24 -0800
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Subject: Re: [PATCH net] net: ethernet: mtk_eth_soc: fix RX data corruption
 issue
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To:     Daniel Golle <daniel@makrotopia.org>, netdev@vger.kernel.org,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Russell King <linux@armlinux.org.uk>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Lorenzo Bianconi <lorenzo@kernel.org>,
        Mark Lee <Mark-MC.Lee@mediatek.com>,
        John Crispin <john@phrozen.org>, Felix Fietkau <nbd@nbd.name>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        DENG Qingfang <dqfext@gmail.com>,
        Landen Chao <Landen.Chao@mediatek.com>,
        Sean Wang <sean.wang@mediatek.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Vladimir Oltean <olteanv@gmail.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Vladimir Oltean <vladimir.oltean@nxp.com>
Cc:     =?UTF-8?Q?Bj=c3=b8rn_Mork?= <bjorn@mork.no>
References: <138da2735f92c8b6f8578ec2e5a794ee515b665f.1677937317.git.daniel@makrotopia.org>
From:   Florian Fainelli <f.fainelli@gmail.com>
In-Reply-To: <138da2735f92c8b6f8578ec2e5a794ee515b665f.1677937317.git.daniel@makrotopia.org>
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On 3/4/23 05:43, Daniel Golle wrote:
> Fix data corruption issue with SerDes connected PHYs operating at 1.25
> Gbps speed where we could previously observe about 30% packet loss while
> the bad packet counter was increasing.
> 
> As almost all boards with MediaTek MT7622 or MT7986 use either the MT7531
> switch IC operating at 3.125Gbps SerDes rate or single-port PHYs using
> rate-adaptation to 2500Base-X mode, this issue only got exposed now when
> we started trying to use SFP modules operating with 1.25 Gbps with the
> BananaPi R3 board.
> 
> The fix is to set bit 12 which disables the RX FIFO clear function when
> setting up MAC MCR, MediaTek SDK did the same change stating:
> "If without this patch, kernel might receive invalid packets that are
> corrupted by GMAC."[1]
> 
> [1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/d8a2975939a12686c4a95c40db21efdc3f821f63
> 
> Fixes: 42c03844e93d ("net-next: mediatek: add support for MediaTek MT7622 SoC")
> Tested-by: Bjørn Mork <bjorn@mork.no>
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian